Phalcon Interview Questions

An overview of Phalcon

Phalcon is a loosely coupled, full-stack PHP 5 framework. It is based on the MVC (model-view-controller) design pattern. As of today, Phalcon is the fastest framework giving high performance compared to any other structure. Phalcon is the first ORM based framework that is written in both C and PHP, each of which can be used in stand-alone mode. This feature-rich framework gives the lowest overhead and reduces the amount of coding a developer has to do. Try our latest Phalcon interview questions that can get you your dream job.

Advantages of Phalcon

  • Innovative architecture
  • High performance, processes more requests per second.
  • They are loosely coupled allowing components to be clubbed as required.
  • Great option for quickly creating REST services
  • Robust framework
  • Readable and easy to understand file structure and code

To understand more about Phalcon and prepare yourself for a job interview, check out our comprehensive list of Phalcon interview questions, that is quick to read and comes in handy during interview preparation.

Latest Version

Phalcon 3.4.3, the latest version has been released on Feb 25, 2019.

Development history

Phalcon was created by Andrés Gutiérrez and some collaborators with the intent of providing high-performance solution for web applications. The name comes by combining PHP and falcon. Interestingly, the first draft of Phalcon was called 'Spark.' The project was moved from C to Zephyr with Phalcon 2.0. Phalcon 3.4.3, the latest version has been released on Feb 25, 2019. This is one of the favourite Phalcon interview questions.

Phalcon Interview Questions and answers

Looking for a new job? Do not miss to read our Phalcon Interview Questions and answers. Whether you are a fresher or an experienced, these questions and answers that can help you to crack your interview.

Phalcon is a full-stack open source framework written in PHP and C (programming languages). It is the first framework that implements object-relational-mapping (ORM) in C. This loosely coupled framework is based on MVC (model-view-controller) architecture. Phalcon runs on PHP 5.4 and is one of the fastest frameworks. Phalcon can be used for end to end web applications that

  • Need to be super-fast and handle more HTTP requests per second
  • Consume less resource (hardware) storage as the C extensions are loaded along with PHP during the web-server start process and are pre-compiled.
Following are the unique features of Phalcon –
  • Fastest full stack framework for PHP
  • Low memory and CPU consumption
  • Supports the standard MVC directory structure.
  • Loosely coupled, the user can use the full framework or use only the required components.
  • Uses Dependency injection pattern for faster location of services
  • First framework to implement ORM (Object-Relational-Mapping)
PHQL is a high-level, object-oriented query language similar to SQL. Phalcon provides a parser written in C that translates syntax into RDBMS. This in-memory parser uses the same technology as SQLite, which is thread-safe, prevents SQL injection and consumes very less memory, thus giving high performance.

In Phalcon, we can increase CSRF (Cross-Site Request Forgery) timeout by increasing the token time as tokens maintain the user sessions. Token time is valid until the session is valid. The session time can be increased by setting session.gc_maxlifetime to a higher value in the php.ini file.

ODM or Object-Document-Mapping is the mapping for NoSQL databases. Phalcon can map documents from NoSQL databases through ODM using a unique ObjectID for each object to be mapped. Phalcon’s ODM offers CRUD functionality, events, validation, and other services. The advantage of ODM is that it is a persistence mechanism where an application model and data source have no dependencies on each other.

Dependency Injection (DI) is a pattern through which appropriate objects or instances of a class are created during run-time rather than compile-time. The class, thus, becomes independent from creating the cases and it is the responsibility of DI to know which class requires what objects and provide the same. In Phalcon, the DI component implements dependency injection and manages the global instances of different classes used in the application.

In Phalcon, routing is managed by its Router component. This component allows the user to define and add custom routes that can be mapped to controllers or handlers that receive the requests from the application. The router parses the incoming URI based on the information received.

To initiate new session,

  • $session = new Session();
  • $session->start();

setting data into session

  • $this->session->set("key", "value");

retrieve session data

  • $this->session->get(“key”);

removing session

  • $this->session->remove(“key”'); //remove particular variable
  • $this->session->destroy(); //remove the session

Lazy initialization is a technique where a class is automatically loaded by the Phalcon class ‘Loader’ during runtime. This greatly improves performance. Auto loader does this in 4 ways i.e. by registering

  • namespaces, $loader->registerNamespaces(…)
  • directories, $loader->registerDirs(…)
  • classes, $loader->registerClasses(…)
  • files $loader->registerFiles(…)

and then registering the auto loader as $loader->register();

Volt is the template engine used in Phalcon. It is fast and designer-friendly. Volt views are compiled in php and have many helpers that make writing views easier and quicker.

There are 2 ways to inject services into Volt -
  • Define the function in the dependency injection container. Access the service in the template with its name. Example - <input name="‘counter’" value="‘{{maxproduct.getCounter()" }}>
  • When Volt is used as a stand-alone component, create a compiler as $compiler = new VoltCompiler(); and compile the template by passing different return parameters.

You can use setVar() or setVars() in the controller’s showAction() method to pass single or multiple variables respectively, directly to the view.

  • $this->view->setVar('productId', $productId);
  • $this->view->setVars( ['username' => $user->username, 'phone' => $contact->phone,] );

Instead of using the above methods, you can also set the variables as $this->view->username = $user->username;

There are 3 database engines supported by Phalcon – Mysql, Postgresql, and SQLite.

1. is a php extension written in C, which is injected into the php core at runtime is a source base on which web developers build their applications
2. offers high performance and fast execution is slower and can process fewer requests compared to Phalcon
3. uses ODM which is fast and has a simple, understandable syntax relies on ORM which supports almost all the databases
4. uses the Volt template engine uses Blade template engine
5. requires root access to be installed doesn’t need root access
6. has fewer forum exchanges and documentation compared to Laravel has a more significant community and more support documentation
There are two types of views in Phalcon –
  • Volt – used when the template engine is written in C and compiled in php, can be used as a stand-alone component.
  • Phtml – used when the template engine is in php itself.
  • .volt files are written in C language and later compiled to php code. These can be used as a stand-alone component and includes a set of highly integrated elements.
  • .phtml files should be created when php is used as a template engine. The view is the default rendering component and is called to execute a particular action. .phtml cannot be used as a stand-alone component.

No need to declare a variable in Phalcon; the variable is created when its value is assigned. Example - $name = “user1”;

Single module applications have only one module. This application does not mandate a namespace. It has a structure as –










Multi-module uses the same document root for all the modules. Each directory in apps has an MVC structure of its own. Module-specific settings are configured using Module.php present in each module. The structure is like –







Module.php backend/




Module.php public/




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